During the requested three years of additional support we wish to continue our work on a wide ranging series of projects to elucidate several related problems: (A) The hypothalamic control of anterior pituitary hormone release with particular emphasis on the control of prolactin, growth hormone and ACTH. This area of research will involve the following projects: (1) further purification of the hypothalamic factors which stimulate and inhibit prolactin release and determination of their nature; (2) an attempt to determine if prolactin releasing factor can be separated from CRF since the physiological evidence is consistent with concept that the two may be identical; (3) further study of the mechanism of action of the factors on the pituitary utilizing a newly developed preparation of dispersed pituitary cells in shortterm culture; (4) more precise localization of the hypothalamic areas involved in prolactin, growth hormond ACTH and TSH release; (5) further investigations of the role of the central monoaminergic systems in the control of the secretion of the above listed pituitary hormones; (6) delineating the role of prostaglandins in the control of the release of these pituitary hormones. (B) Study of the effect of stress on the activity of the hypothalamic pituitary system with emphasis on the release of prolactin, GH and ACTH and a complementary study of the role of these homones in systemic changes associated with stress. (C) Examination of the physiological importance of extra-pituitary actions of GIF and TRF (and other factors if they become available).